The present invention relates to a device for use in a video tape recorder or like magnetic record reproducing apparatus for transporting a cassette between a loading position and an operative position.
As a cassette loading-unloading system for video tape recorders and like magnetic record reproducing apparatus, recently in use is a cassette front loading-unloading system which has a cassette inlet in a front portion of the main body of the reproducing apparatus and a cassette support adapted to receive a cassette inserted from the inlet and movable along a cassette frame horizontally rearward and then vertically downward to an operative position. For the ejection of the cassette, the cassette support is moved reversely to return the cassette to the loading position. The transporting device of this type of cassette loading-unloading system comprises guide means for guiding the cassette support along the abovementioned path, and drive means including a motor serving as a drive source for moving the cassette. However, the cassette transporting device has the following drawbacks.
The guide means generally comprises a guide member having a horizontal groove and vertically movably provided on each of opposite side walls of the cassette frame, and a projecting guided portion formed on each of opposite side walls of the cassette support and slidably fitted in the horizontal groove in the guide member. The cassette support is moved horizontally and vertically by moving the guided portion horizontally along the horizontal groove and then moving the guide member downward. The guide means nevertheless has a fundamental drawback; since the area of contact between the guided portion and the guide member is small, the engagement therebetween invariably involves a backlash, so that the cassette support is liable to tilt or deflect sidewise during horizontal travel, hence unstable movement. The guide member is made vertically movable along a vertical groove formed in the side wall of the cassette frame by a pin externally projecting from the guide member and loosely fitted in the vertical groove. Accordingly the engagement of the pin in the vertical groove also involves a backlash, which renders the vertical movement of the cassette support also unstable.
On the other hand, the drive means comprises exactly identical drive gear assemblies respectively provided externally on opposite side walls of the cassette frame and interconnected by a power transmission shaft extending between the side walls of the cassette frame. The shaft is driven by a motor at one side to simultaneously drive the two drive assemblies and to thereby move the opposite sides of the cassette support at the same time. However, with this arrangement wherein the two drive assemblies must be disposed on opposite sides of the cassette frame, the drive means in its entirety is complex in construction, costly in respect of component parts and assembly and is further inefficient to assemble. Moreover, the two drive assemblies are not always accurately operable in synchronism due to differences in precision or improper operation of one of the assemblies, resulting in the likelihood that the cassette support will not move properly.